SS8550-D-AP Equivalent & Substitute Parts

Part Overview

The SS8550-D-AP is a PNP bipolar junction transistor manufactured by Micro Commercial Co, rated for 25 V collector-emitter breakdown voltage and 1.5 A maximum collector current in a Through Hole TO-92 package. This device is classified as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. The SS8550-D-AP serves in small-signal switching and amplification circuits requiring PNP transistor functionality within the specified voltage and current ratings.

Substiute Parts

SS8550-D-AP

Micro Commercial CoIn Stock: 796SS8550-D-AP Datasheet

Current PartRFQ

SS8550CTA

Fairchild SemiconductorIn Stock: 41321SS8550CTA Datasheet

MFR RecommendedRFQ

SS8550DTA

onsemiIn Stock: 45141SS8550DTA Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SS8550-D-AP is determined by strict equivalence across the following electrical and mechanical parameters:

Critical Matching Parameters:

• Transistor polarity: PNP
• Maximum collector current: 1.5 A
• Maximum collector-emitter breakdown voltage: 25 V
• Maximum power dissipation: 1 W
• Mounting configuration: Through Hole
• Package type: TO-92-3 (TO-226AA Formed Leads)

The substitute parts SS8550CTA and SS8550DTA meet all critical electrical specifications and mechanical compatibility requirements. Both devices maintain identical voltage and current ratings, support the same through-hole mounting footprint, and operate within compatible temperature ranges. Transition frequency specifications (200 MHz for both substitutes versus 190 MHz for the main part) remain within acceptable performance parameters for small-signal applications.

Parameter Comparison

Engineering Selection Recommendations

SS8550CTA (Fairchild Semiconductor): This substitute is classified as Active product status, ensuring continued availability and manufacturing support. The device is packaged in Bulk format and maintains full electrical equivalence to the SS8550-D-AP across all critical parameters. The lower Vce saturation voltage (500mV versus 800mV) represents improved switching efficiency in saturation mode. Inventory availability is substantial at 41,300 pieces.

SS8550DTA (onsemi): This substitute is classified as Active product status with ROHS3 compliance certification, meeting current regulatory requirements. The device maintains DC current gain specifications identical to the main part (160 @ 100mA, 1V) and is supplied in Cut Tape format. Transition frequency is 200 MHz, providing enhanced high-frequency performance. Inventory availability is 45,100 pieces. REACH Unaffected status confirms regulatory compliance for European markets.

Both substitutes are electrically and mechanically compatible with the obsolete SS8550-D-AP and support direct replacement in through-hole PCB applications without circuit redesign.

Frequently Asked Questions (FAQ)

Q: Can SS8550CTA and SS8550DTA be used interchangeably with SS8550-D-AP?

A: Yes. Both substitutes meet the critical electrical specifications: 1.5 A maximum collector current, 25 V collector-emitter breakdown voltage, 1 W maximum power dissipation, and TO-92-3 through-hole package configuration. Mechanical footprint compatibility is identical.

Q: What is the significance of the Vce saturation difference between the main part and substitutes?

A: The SS8550-D-AP specifies 800mV Vce saturation, while both SS8550CTA and SS8550DTA specify 500mV. The lower saturation voltage in substitutes indicates reduced voltage drop during transistor saturation, resulting in lower power dissipation and improved switching efficiency in saturated switching applications.

Q: Are there compliance differences between the two substitutes?

A: SS8550DTA carries ROHS3 compliance and REACH Unaffected certification, meeting current environmental regulations. SS8550CTA compliance status is not specified in available documentation. For applications requiring documented regulatory compliance, SS8550DTA is the preferred selection.

Q: Does the 10 MHz higher transition frequency in substitutes affect circuit performance?

A: Both substitutes operate at 200 MHz transition frequency versus 190 MHz for the main part. This 5% increase provides enhanced high-frequency performance and does not degrade compatibility with circuits designed for the original 190 MHz specification.

Q: What packaging formats are available for these substitutes?

A: SS8550CTA is supplied in Bulk packaging; SS8550DTA is supplied in Cut Tape format. Both formats are compatible with standard component handling and assembly processes. Selection depends on procurement and assembly workflow requirements.

Q: Are there inventory considerations for long-term supply?

A: Both substitutes maintain substantial active inventory: SS8550CTA (41,300 pieces) and SS8550DTA (45,100 pieces). Active product status for both devices ensures continued manufacturing availability, eliminating supply risk associated with the obsolete SS8550-D-AP.